The classical folding camera is one in which a lens carrier for an objective lens is translatable along the lens optical axis between a storage position retracted in the camera body and a picture-taking position extended from the camera body. Typically, a lens cover is pivotally connected to the camera body for swinging movement between a closed or folded position in front of the objective lens when the lens carrier is in its storage position and an opened or unfolded position removed from the objective lens when the lens carrier is in its taking position. See commonly assigned U.S. Pat. No. 4,557,571, for example.
In a folding camera such as disclosed in the '571 patent, when the lens cover is swung from its opened position to its closed position, it pushes the lens carrier inwardly of the camera body to translate the lens carrier from its taking position to its storage position. Conversely, when the lens cover is swung from its closed position to its opened position, spring means are free to push the lens carrier outwardly of the camera body to translate the lens carrier from its storage position to its taking position.
A further U.S. Pat. No. 4,365,884 shows a folding camera wherein the lens carrier is associated with the lens cover to extend to the taking position as the lens cover is swung to its opened position and to retract to the storage position as the lens cover is swung to its closed position. A locking device is provided for locking the lens carrier in its picture taking position. The lens carrier includes an integral pin which, when the lens carrier is moved to its taking position, passes beneath a latching lever to come to rest at the far side of the latching lever, where it is retained by the latching lever. An intricate linkage is needed to separate the latching lever from the pin to allow the lens carrier to be returned to its storage position.
In commonly assigned U.S. Pat. Nos. 5,212,510 and 5,231,436, compact cameras are disclosed having a flash unit combined in a flip open lens cover which, in a folded closed position, covers the camera taking lens assembly. A retractable lens carrier operates as the lens cover is flipped open or closed to move the camera taking lens assembly outward to a picture-taking position or inward to a storage position, respectively. The flash unit built into the end of the flip open lens cover is separated from the taking lens a distance that helps alleviate "red eye".
In the '436 patent, a locking device locks the lens carrier in a fixed picture-taking position, and a single cam piece disengages the locking device on manual movement of the lens cover to the closed position to allow retraction of the lens carrier to its storage position.
In the '510 patent, the lens cover is made elastic, or includes an elastic pad piece, to avoid abrasion of the taking lens on closure of the lens cover. A mechanism is described for flipping up and returning down a front range finder lens when the lens cover is flipped open and closed, respectively. No particular mechanism is shown for advancing and retracting the lens carrier between the picture taking and storage positions.
In a modern, compact auto focus camera, the camera is provided with a motorized lens drive mechanism for moving the taking lens to a proper in-focus position in response to a signal from a range finding system. In the context of a flip open lens cover of the type shown in the above-referenced patents and as employed in the KODAK.RTM. Cobra camera models, this movement of the lens carrier from the storage position to an in-focus position and back to the storage position must occur while the lens cover is flipped up and before the lens cover can be flipped down again, respectively.
In today's marketplace, customers are asking for small, compact, "point and shoot" cameras which they can take anywhere comfortably. The customer also wants the interval time between each picture taking sequence to be minimized, typically 200-300 milliseconds for a non-flash exposure. In all such compact folding cameras, a danger exists that the lens cover may be forced closed before the taking lens assembly has time to retract to the storage position. This is particularly true when the lens carrier is driven by a lens focus motor under the control of an auto-focus control system to an extended position for taking a picture, and the lens cover can be flipped closed faster than the lens focus motor can operate. This could have an effect on the camera's ability to focus the lens. Such failure modes will cause customers to return their cameras and ultimately cause customer dissatisfaction.